One of the last two ribs. A rib is said to be "fluctuating" if it does not attach to the sternum (the breast bone) or to another rib. There are usually 12 pairs of ribs in all. Each pair of ribs is attached to the building blocks of the spine (the vertebrae) in the back. The 12 pairs of ribs consist of: True ribs: The first seven ribs attach to the sternum (the breast bone) in the front and are known as true (or sternal) ribs. False ribs: The lower five ribs do not directly connect to the sternum and are known as false ribs. The upper three false ribs connect to the costal cartilages of the ribs just above them. The last two false ribs, however, usually have no ventral attachment (no anchor at all in front) and are called fluctuating, floating, or vertebral ribs.

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Fluctuating rib — One of the last two ribs. A rib is said to be fluctuating if it does not attach to the sternum (the breast bone) or to another rib. There are usually 12 pairs of ribs in all. Each pair of ribs is attached to the building blocks of the spine (the… … Medical dictionary

Rib — One of the 12 paired arches of bone which form the skeletal structure of the chest wall (the rib cage). The ribs attach to the building blocks of the spine (vertebrae) in the back. The 12 pairs of ribs consist of: True ribs: The first seven ribs… … Medical dictionary

Rib, sternal — One of the first 7 pairs of ribs. A rib is said to be a sternal rib or a true rib if it attaches to the sternum (the breast bone). All 12 pairs of ribs attach to the building blocks of the spine (vertebrae) in the back. The 12 pairs of ribs… … Medical dictionary

Rib, floating — One of the last two ribs. A rib is said to be floating if it does not attach to the sternum (the breast bone) or to another rib. There are usually 12 pairs of ribs in all. Each pair of ribs is attached to the building blocks of the spine (the… … Medical dictionary

Rib, vertebral — One of the last two ribs. A rib is said to be vertebral if it does not attach to the sternum (the breast bone) or to another rib. There are usually 12 pairs of ribs in all. Each pair of ribs is attached to the building blocks of the spine (the… … Medical dictionary

Rib, false — One of the last 5 pairs of ribs. A rib is said to be false if it does not attach to the sternum (the breast bone). All 12 pairs of ribs attach to the building blocks of the spine (vertebrae) in the back. The 12 pairs of ribs consist of: True ribs … Medical dictionary

Rib, true — One of the first 7 pairs of ribs. A rib is said to be true if it attaches to the sternum (the breast bone). All 12 pairs of ribs attach to the building blocks of the spine (vertebrae) in the back. The 12 pairs of ribs consist of: True ribs: The… … Medical dictionary

False rib — One of the last 5 pairs of ribs. A rib is said to be false if it does not attach to the sternum (the breast bone). All 12 pairs of ribs attach to the building blocks of the spine (vertebrae) in the back. The 12 pairs of ribs consist of: True ribs … Medical dictionary

Floating rib — One of the last two ribs. A rib is said to be floating if it does not attach to the sternum (the breast bone) or to another rib. There are usually 12 pairs of ribs in all. Each pair of ribs is attached to the building blocks of the spine (the… … Medical dictionary

Sternal rib — One of the first 7 pairs of ribs. A rib is said to be a sternal rib or a true rib if it attaches to the sternum (the breast bone). All 12 pairs of ribs attach to the building blocks of the spine (vertebrae) in the back. The 12 pairs of ribs… … Medical dictionary